The Mitsubishi i-MIEV battery electric vehicle took the top spot from the Honda Civic Natural Gas, which has held on to first place for eight years in a row.

The i-MIEV earned a score of 58 in the annual survey, the highest Green Score to be awarded since the ranking system began back in 1998. The car, debuting in the American market this year, has a combined city and highway fuel economy of 112 miles per gallon equivalent, which ranks it as one of the most efficient vehicles to drive in the United States.

"Even taking into account the emissions generated from the electricity used to power the i-MIEV, it still handily outscores other vehicles on the market today," ACEEE lead vehicle analyst Shruti Vaidyanathan said in a statement.

Coming in second on the Greenest Vehicle List were the Honda Civic Natural Gas and the Nissan Leaf, which tied with a score of 55. The Honda Natural Gas had held the top spot for eight years running, and was recently named the winner of the 2012 Green Car of the Year Award at the LA Auto Show. The Honda had been upgraded this year with improved fuel economy.

The vehicles ranked in the survey are analyzed on the basis of a "Green Score," a singular measure that incorporates unhealthy tailpipe emissions, fuel consumption, and emissions of gases that contribute to climate change.

Other notable, sportier green cars that made the list include the Honda CRZ hybrid two-seater with a green score of 50 and the Scion IQ with a core of 52.